The present invention is directed to a method and a system permitting a user of a legacy telephone system, i.e. a Public Service Telephone System (PSTN), an Integrated Service Digital Network (ISDN), or a Mobile telephony system (MTS), to publish information about his or her presence or availability in an interconnected presence system, for example and preferably to an Internet presence service.
In the environment of telephony there is a strong interest in making a call succeed, not only from a user""s point of viewxe2x80x94he/she wants to communicate with another userxe2x80x94but also from that of the service provider, i.e. the need to generate revenue. There is also an interest in preventing unsuccessful calls. Having a calling user re-dial a number again and againxe2x80x94either because the called user is busy or because he/she does not answerxe2x80x94is unproductive, because unsuccessful call attempts are usually not charged although they consume a lot of network resources.
Several supplementary services could be available to help a calling user in the cases mentioned above, such as among others, Completion of Call to Busy Subscriber (CCBS), Completion of Call on No Reply (CCNR), call back, etc.
To implement those services, the system usually monitors the status of the called user and automatically retries the call when the called user is no longer busy (in case of CCBS) or when the called user is available again (in case of CCNR).
However, there is substantially no deployment of such supplementary services in public telephone networks because these services would require complicated interaction between the users and the switches, and between the switches themselves. Even in a more modern Private Branch eXchange (PBX) environment it does happen that such services are offered only to those users that are connected to the same PBX.
xe2x80x9cPresencexe2x80x9d is a mode of communication that has recently become popular in the Internet. It is a service that allows a user xe2x80x9cAxe2x80x9d to declare his interest in the presence or availability information of another user xe2x80x9cBxe2x80x9d. User xe2x80x9cAxe2x80x9d is said to subscribe to the xe2x80x9cpresence informationxe2x80x9d of user xe2x80x9cBxe2x80x9d. The terminal of user xe2x80x9cBxe2x80x9d publishes xe2x80x9cpresence informationxe2x80x9d about user xe2x80x9cBxe2x80x9d. The service delivers notifications to xe2x80x9cAxe2x80x9d each time the xe2x80x9cpresence informationxe2x80x9d of xe2x80x9cBxe2x80x9d changes.
In connection with the Internet, for example, xe2x80x9cpresence informationxe2x80x9d about a user is information about the user""s presence orxe2x80x94in a more restricted sensexe2x80x94about his/her degree of availability for interaction with the telecommunication system. For example, such information may include whether or not the user is active in the Internet.
However, to the best of applicant""s knowledge, it is not possible, at present, for a user of an Internet presence service to obtain similar or equivalent presence information about a user of a legacy telephone system.
Accordingly, it is an object of the invention to provide for a method and system for providing an indication of availability of a user of a legacy telephone system to a user of an interconnected presence service, e.g. an Internet presence system.
More specifically, the present invention aims at providing a method and system that permits a user of a legacy telephone system to publish information about her/his availability for communication with other users of any interconnected presence system, e.g. such that an Internet user who has subscribed to the availability information of a legacy telephone user could then be notified about the availability of such user.
This object and further advantages will achieved, according to a first general embodiment of the invention by a method of operating an availability service as specified in claims 1 and 12; preferred embodiments of the inventive method are as defined in the claims.
According to a second general embodiment, the invention provides for a system of operating an availability service as specified in claim 6; preferred embodiments of the inventive method are as defined in the claims.
According to a third general embodiment, the invention provides for an availability service program for implementing operation of an availability service as specified in claim 10.
According to a further embodiment, the invention provides for a module as specified in claim 11 for operating an availability service.
Generally, legacy telephone systems collect presence information about their users but for internal purposes and without offering a presence service to their users: For example, a PSTN is able to monitor the status of a telephone line of a subscriber and determine whether the user is busy or not. The event that a telephone line goes from busy state to free state is a piece of presence information for use according to the invention. It is of interest because it indicates that during a subsequent period of time, e.g. the next couple of seconds or minutes, there is a high likelihood that the user is able to answer a call.
Further, networks for mobile telephony provide a procedure for the mobile telephones to register with the base station before the mobile telephone can make or receive a call. The network keeps track of the registration status. The fact that a mobile telephone is registered and not involved in a call also is another piece of information for use in the present invention. It is of interest because it indicates that there is a high likelihood that the user is able to answer a call.
Generally speaking, a PTSN user is either busy or not. For the present invention, a signal indicating transition from busy to not busy indicates that during a subsequent period of time xcfx84, there is a relatively high probability that the user will answer an incoming call and is present in the sense of the invention. It should be noted, however, that the term xe2x80x9cpresence of a userxe2x80x9d does not necessarily imply actual physical presence but, rather, an indication of xe2x80x9cavailabilityxe2x80x9d of a user. This distinction is of importance because xe2x80x9cpresencexe2x80x9d is a xe2x80x9cdigitalxe2x80x9d concept in that a user is either present, or he is not present. xe2x80x9cAvailabilityxe2x80x9d, on the other hand, could be said to be xe2x80x9cgradedxe2x80x9d so that the a certain degree of a user""s availability could be defined, e.g. a xe2x80x9chighxe2x80x9d, xe2x80x9cmediumxe2x80x9d or xe2x80x9clowxe2x80x9d degree of availability. For this reason, the term xe2x80x9cavailability signalxe2x80x9d rather than xe2x80x9cpresence signalxe2x80x9d is used herein even though both terms could be used synonymously as well.
The following terms and concepts are used herein to define the presence or availability status of a PSTN:
xe2x80x9cBusyxe2x80x9d: a signal indicating that the user is currently involved in a call.
xe2x80x9cProbably Availablexe2x80x9d: a signal indicating that the user has just been involved in a call and is now free, and that it is probable that the user will answer an incoming call. This state or signal is termed a xe2x80x9chigh availabilityxe2x80x9d state or signal, respectively, and will change into xe2x80x9cavailability unknownxe2x80x9d after a certain time period xe2x80x9cxcfx84xe2x80x9d as defined below. Hence,
xe2x80x9cAvailability Unknownxe2x80x9d is the state or signal indicating that the user has not been busy for a period of time greater than xcfx84.
The time period xcfx84 is a configurable variable of the system according to the invention and can vary between minutes to hours. It is intended to characterize the fact that the longer a user is not busy, the smaller is the probability that he will be available for respond to an incoming call.
Additionally, the system or user may be provided with a means for xe2x80x9cresettingxe2x80x9d the user""s status to xe2x80x9cunknownxe2x80x9d; for example, the user may generate a specific signal, e.g. dial a certain code which is reserved for that purpose.
An important advantage of the presence or availability status that can be published by means of a system or method according to the invention is that the user can influence his status via a very simple interface: he can move his status to the state xe2x80x9cprobably availablexe2x80x9d by briefly picking up his telephone handset. There is no need for typing complicated and difficult to remember access codes
For a user of a mobile telephone system, an additional state xe2x80x9cUnregisteredxe2x80x9d is introduced to account for the registration status of the mobile user. Preferably, a user of a mobile telephone system should be able to set to a longer value for T than a PSTN user.